Comprehensive Organic Molecules: Structures, Functional Groups, and Biological Roles

How do carbon chains form and what structures can they take?

Carbon atoms bond covalently, forming chains that can be straight, branched, or ring-shaped.

What is the difference between organic and inorganic molecules?

Organic molecules contain carbon-hydrogen bonds, while inorganic molecules generally do not.

How are hydrocarbon structures formed?

When carbon bonds with hydrogen in chains, rings, or branched structures.

What are the six common functional groups?

Hydroxyl, carbonyl, carboxyl, amino, sulfhydryl, and phosphate; formed by adding atoms/groups to hydrocarbons.

How do isomers, stereoisomers, and structural isomers differ?

Isomers have the same formula but different structures. Structural isomers differ in bonding order, stereoisomers differ in spatial arrangement.

How are water molecules involved in functional group reactions?

Dehydration removes water to build molecules; hydrolysis adds water to break them down.

What is polymerization?

The process of joining monomers into polymers through dehydration reactions.

What are carbohydrates and how are chains formed?

Carbohydrates are sugars composed of C, H, and O; chains form through glycosidic bonds between monomers.

How are carbohydrates stored in animal and plant cells?

Animals store glycogen; plants store starch.

What's the difference among monosaccharides, disaccharides, and polysaccharides?

Monosaccharides = single sugars, disaccharides = two sugars, polysaccharides = long chains.

What forms do monosaccharides take?

They can exist in linear or ring forms, and as aldoses or ketoses.

How are glycosidic bonds formed?

By dehydration reactions linking two monosaccharides.

What are the four common polysaccharides?

Starch, glycogen, cellulose, and chitin.

What are the three main types of lipids?

Triglycerides, phospholipids, and steroids.

How do the three main lipids differ?

Triglycerides store energy, phospholipids form membranes, steroids regulate signaling and structure.

What are the two types of neutral lipids?

Fats (solid at room temp) and oils (liquid at room temp).

Saturated vs. unsaturated fatty acids?

Saturated have no double bonds; unsaturated have one or more double bonds.

How do phospholipids arrange in polar environments?

They form bilayers with hydrophilic heads outward and hydrophobic tails inward.

Role of phospholipids in protocells?

They self-assemble into bilayers, creating primitive membranes.

Structure and properties of steroids?

Steroids have four fused carbon rings with various functional groups.

Steroids in plant and animal membranes?

Cholesterol in animals and phytosterols in plants stabilize membranes.

How do steroids function as hormones?

They act as signaling molecules, regulating processes like metabolism and reproduction.

Functional groups in steroid hormones?

Functional groups determine hormone type (e.g., estrogen vs. testosterone).

Other lipids unrelated to triglycerides, phospholipids, or steroids?

Waxes, pigments, and vitamins (like carotenoids).

What are the ten types of proteins and their functions?

Structural, enzymatic, transport, hormonal, defensive, storage, contractile, receptor, motor, and regulatory.

Define amino acid.

monomers of proteins, consisting of an amino group, carboxyl group, hydrogen, and side chain.

How do cells use 20 amino acids to make proteins?

Ribosomes link amino acids in sequences dictated by mRNA.

Role of amino acid side groups?

Side chains determine chemical properties and protein folding.

Four structural levels of proteins?

Primary, secondary, tertiary, quaternary.

Importance of primary structure?

Determines overall protein shape and function.

Two common secondary structures?

Alpha helices and beta-pleated sheets.

Denaturation and renaturation?

Denaturation is protein unfolding; renaturation is refolding under the right conditions.

Protein domains?

Independently folding functional regions within proteins.

Glycoproteins vs. nucleoproteins?

Glycoproteins have carbohydrate groups; nucleoproteins contain nucleic acids.

Characteristics of DNA and RNA?

DNA is double-stranded, stores genetic info; RNA is single-stranded, aids in protein synthesis.

Three components of nucleotides?

Phosphate group, sugar, nitrogenous base.

Deoxyribonucleotides vs. ribonucleotides?

DNA uses deoxyribose; RNA uses ribose.

Nucleosides?

Molecules made of a sugar and base, without phosphate.

Phosphodiester bond?

Links nucleotides by connecting phosphate of one to sugar of another.

ATP and GTP?

High-energy molecules with three phosphate groups, used for energy and signaling.

Double helix of DNA?

Two strands twisted with complementary base pairing.

Compare DNA and RNA structures.

DNA = double-stranded, thymine; RNA = single-stranded, uracil.